Floating bridge consisting of a number



Nov. 8, 1955 BOQNSTRA 2,722,699

FLOATING BRIDGE CONSISTING OF A NUMBER OF SECTIONS WHICH PREFERABLY ARE MUTUALLY EQUAL Filed Aug. 29, 1952 FIG.I

INVENTOR Lisa :4); 14 Q5 dumSfv United States PatetitO FLOATING BRIDGE CONSISTING OF A NUMBER OF SECTIONS WHICH PREFERABLY ARE MU- TUALLY EQUAL Lieuwe Lucas Boonstra, Amsterdam, Netherlands, as-

signor to N. V. Hollandsche Draad-En Kabelfabriek, iXmdSterdam, Netherlands, a company of the Netheran s Application August 29, 1952, Serial No. 307,114

Claims priority, application Netherlands September 1, 1951 1 Claim. (Cl. 1427) The invention relates to a floating bridge consisting of alplurality of sections which preferably are mutually equa The invention has the object to provide a floating bridge of the above-mentioned type which can be assembled and disassembled very quickly and without trouble. The bridge is particularly suitable for military purposes. For that purpose according to the invention each section is composed of a plurality of superimposed sheets, one or more of which are staggered so that a space is obtained between the non staggered sheets in which space the staggered part of the staggered sheet of another section of the floating bridge fits.

In a preferred embodiment of the floating bridge according to the invention each section is manufactured from a polycellular synthetic resin material, e. g. cellpolyvinylchloride.

This material has a specific gravity which is below 1 and moreover has the advantages that it maintains its form, that it is water and weather resistant, does not decay or grow mouldy and does not take up water.

Since it is very light the sections can very easily be transported. If desired, however, other suitable polycellular materials can be used.

According to the invention the sheets of each section are mutually connected by a number of rods and cords which are manufactured from a water-repellant material, while they are provided at their upperand/or underside with a running surface, e. g. from multiplex, which is fixedly connected with the sheets. All fixations are obtained by making use of water-repellant material.

In order to hold the various sections of an assembled floating bridge fast in respect of each other each section according to the invention is provided with cords of a water-repellent material which each at the one side are fixedly connected with the section to which they appertain and at the other side can be coupled with the adjacent section of the bridge.

The rods can e. g. be manufactured from polyethylene and the cords from polyvinylidenechloride (Saran) although other suitable materials can also be used.

In the annexed drawing a preferred embodiment of a part of the floating bridge according to the invention is represented.

Figure 1 is a side view of a section of the bridge.

Figure 2 is a top view or a bottom view thereof.

Figure 3 is an end view of a section.

Figure 4 is a side view of a number of mutually connected sections.

In the embodiment represented the floating bridge is composed of a number of uniform sections floating on the water each comprising three superimposed sheets 1, 2 and 3 of equal measures and manufactured from a polycellular material. The middle sheet 2 of each section is arranged in a staggered position in respect to the two outer sheets 1 and 3 which are not staggered mutually.

In this manner in each section at one side a space 4 gered in respect of the outer sheets 1 and 3 must be the 2 same for all sections of the same bridge, in order that the sections of the assembled bridge rest entirely or substantially entirely against each other. i In this manner a great degree of stability is obtained, especially in longitudinal direction.

The three sheets 1, 2 and 3 of each section are immovably connected with each other with the aid of parallel rods 5 which are arranged transversely over the outer sheets 1 and 3 of the section and which are perpendicular to the longitudinal direction of the bridge.

The rods 5 are manufactured from a material which floats on water, e. g. polyethylene and is water and weather resistant. In the embodiment represented at both sides of each section two rods 5 are present (Fig. 2) which both are arranged in such a manner that the three sheets 1, 2 and 3 are between them (Fig. 1).

Two superimposed rods 5 at both sides of each section are connected by means of a shorter rod 6, preferably manufactured from the same material as the rods 5. At the side of each section (see Fig. 1) there are in this case, consequently, two short connecting rods 6 which are again mutually connected by a cord 7, manufactured e. g. from polyvinylchloride or polyvinylidene chloride (Saran). This cord runs at the half height of the section and is fixedly connected with each of its ends to a sheet 8 which at the half height of each rod 6 is fixedly connected therewith. Also the sheets 8 consist of the same material as the rods 5 and 6.

On the top side and bottom side of each section a shelf 9 is mounted, e. g. from multiplex. These sheets 9 have such dimensions that they are in alignment in the longitudinal direction of the assembled bridge and form a continuous running surface (Fig. 4). The width of the shelves 9 is smaller than that of the sheets of the sections (vide Fig. 2). By means of a plurality of bolts or pins 10, which e. g. also are manufactured from polyethylene, the shelves 9 are fixedly connected with the sheets 1 and 3. The space which would be obtained as a result of the presence of the rods 5 between a shelf 9 and the outer sheet 1 or 3 is filled up with a layer of polycellular material 11 (Fig. 3), preferably of the same material from which the sheets are manufactured. The width of the layer 11 is equal to the width of the shelf 9. The variout sections of the floating bridge are mutually connected in a very simple manner.

For that purpose each section carries at both sides a cord 12 of e. g. polyvinylidenechloride (Saran) which at the one side is fixedly connected with the sheet 8 of the section to which the cord appertains and at the other side has e. g. a safety pin or hook 13 (Fig. 4) which can be put through an opening in the sheet 8 of the adjacent section.

When assembling the bridge it, consequently, is only necessary to insert the middle sheet 2 in the space between the sheets 1 and 3 of the preceding section and thereupon to fix the cords 12.

Although the sections in the example described consist of three sheets, the invention is not restricted thereto. Sections composed of another number of sheets are also conceivable. The section can e. g. be composed of five sheets, the even numbered sheets of which stagger. Another not yet mentioned advantage of the form of the sections is that the top side and bottom side of the section are entirely equal so that this need not be taken into account when assembling the floating bridge. assembling is considerably shortened hereby.

What is claimed is:

A floating bridge comprising a plurality of separate sections of uniform size, each section consisting of at least three superimposed plates of a buoyant and water repellent synthetic resin material having a cellular structure composed of minute cells, said plates being fixed The together, at least one of said plates being staggered with relation to the other plates in such a manner that at least one groove is formed between the unstaggered plates at one end of each section, and at the other end of each section at least one plate projects to form a tongue fitting in a groove of an adjacent bridge section, and connecting members of a buoyant water repellent material coupling said sections.

References Cited in the file of this patent UNITED STATES PATENTS 201,728 White Mar. 26, 1878 1,908,714 Schneider May 16, 1933 2,336,235 Fischer Dec. 7, 1943 2,430,178 Kurfiss Nov. 4, 1947 2,447,056 Cooper Aug. 17, 1948 2,540,831 Pfleumer Feb. 6, 1951 

